The progress of technologies brings significant convenience for lives. In particular, the researches and improvements in the lighting technology enable tremendous color variations for lives. In recent years, light-emitting diodes (LEDs) have appeared, driving enormous progresses in the lighting technology. LEDs are semiconductor devices. Initially, they are applied to indicators and displays. Thanks to the introduction of white-light LEDs, LEDs can now be applied to lighting. They are novel light sources in the 21st century equipped with the advantages of high efficiency, long lifetime, and invulnerability to breakage. Thereby, traditional light sources are not comparable to LEDs. When a forward voltage is applied, LEDs can emit monochromatic and discontinuous light, which is a kind of electroluminescence. By altering the chemical compositions of the adopted semiconductor materials, LEDs can emit near-ultraviolet, visible, or infrared light.
The light emission of LEDs is characterized by straight-line emission. If LEDs are to be adopted as the lighting apparatus, optical lenses or optical microstructures should be used concurrently to alter the straight-lined light emitted by LEDs and result in scattered lighting effects. The optical lenses or optical microstructures can be fully reflective, half reflective, refractive, or scattering optical structures. In general, the light-emitting structures of LEDs can be categorized into edge-lit and direct-lit light-emitting structures. Currently, the edge-lit light-emitting structure is the mainstream structure.
According to the prior art, the light-emitting paths of edge-lit backlight modules can be roughly divided into two types. The first light-emitting path is that after the light emitted by LEDs passes through the light guide plate, it emits from the light-emitting surface directly. The second light-emitting path is that after the light emitted by LEDs passes through the light guide plate, it illuminates onto the reflective housing and then onto the light guide plate by reflection from the reflective housing. Finally, the light emits from the light-emitting surface via the light guide plate. By using the latter method, most light from LEDs will still emit via the light guide plate. Then the intensity of the light emitted from LEDs directly is high. If the light illuminates human eyes directly, glare will result.
The present invention improves the drawbacks of the prior are and provides a light-emitting apparatus with most emerging light being formed by single reflection. Accordingly, the light intensity is weaker than that of direct emission. Then the risk of injuring eyes is relatively lower.